I will admit right off the bat that I'm usually a short term cooker on my BGE, hamburgers or steak for dinner which don't take a lot of finesse with the temp. But occasionally I like ribs or pork butt or would really like to try a brisket but struggle with the temp control. On advice from this forum, I invested in a digital thermometer to get a true reading on my heat and found my BGE thermometer was off about 25 degrees. I cooked a pork butt last week, got the temp to 280, by fiddling with both the top and bottom vets got it to hold for about an hour, HORRAY!! Then the temps started dropping, more messing, back up, over 280, messing, down, up, down, up down. How in the world do you guys get it to keep the same temp for hours? What am I doing wrong?? I put a new gasket on, I make sure the bottom holes are clear and I filled the firebox about half way up the second ring to have enough coals. What am I don't wrong??